Diabetes is a metabolic disorder in which the body cannot properly store and use the energy found in food.
More specifically, diabetes is a condition that affects the body’s ability to use glucose (a type of sugar) as fuel. Glucose is a form of carbohydrate that comes from foods such as breads, cereals, pasta, rice, potatoes, fruits and some vegetables. Glucose is also synthesized in the liver and is carried in the blood to the rest of the body to fuel cellular processes.

To use glucose as fuel, insulin is required to get the glucose into cells. Insulin is a hormone (a type of chemical messenger) made by specialized cells in the pancreas. Insulin regulates blood glucose by stimulating the removal of glucose from the blood and its uptake into muscle, liver and fat cells where it can be stored for energy.
Sometimes the body does not make enough insulin or the cells do not respond properly to insulin. Blood glucose levels can then become elevated while the cells are deprived of fuel. When blood glucose levels get too high (hyperglycemia) this can cause damage to the tiny blood vessels in the eyes, kidneys, heart and nervous system, which is why diabetes is associated with an increased risk of cardiovascular disease, kidney disease, loss of vision and neurological conditions.

Persistently elevated blood glucose may lead to a diagnosis of prediabetes or diabetes. Prediabetes describes the condition where blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes.

There are three types of diabetes:

Type 1 diabetes used to be known as insulin-dependent diabetes, or juvenile-onset diabetes as it often begins in childhood. Type 1 diabetes is an autoimmune condition where the immune system wrongly identifies and subsequently attacks the pancreatic cells that produce insulin, leading to little or no insulin production.

Type 2 diabetes used to be known as non-insulin dependent diabetes or adult onset diabetes, but it is increasingly common in children, largely due to children being more likely to be obese or overweight. In this condition, the body usually still produces some insulin, but this is not enough to meet demand and the body’s cells do not properly respond to the insulin. The latter effect is called insulin resistance, where persistently elevated blood glucose has caused cells to be overexposed to insulin, making them less responsive or unresponsive to the hormonal messenger. Often this type of diabetes can be controlled through improved diet and increased physical activity.

Gestational diabetes occurs in pregnancy and typically resolves after childbirth. People who have experienced gestational diabetes do, however, have an increased risk of developing type 2 diabetes after pregnancy.